Spark plug



W. E. LYONS SPARK PLUG Filed April 11. 1921 Patented Dec. 2, 1924.

UNITED STATES WILLARD E. LYONS, OF CHICAGO, ILLINOIS.

SPARK PLUG.

Application filed April 11, 1921. Serial No. 460,232.

To all whom it may concern:

Be it known that I, VILLARD E. LYoNs, a citizen of the United States,and a resident of the city of Chicago, in the county of Cook and Stateof Illinois, have invented certain new and useful Improvements in aSpark Plug; and I do hereby declare that the following is a full, clear,and exact description of the same, reference being had to theaccompanying drawings, and to the numerals of reference marked thereon,which form a part of this specification.

This invention relates to a spark plug and particularly to a spark plugwhich is provided with an auxiliary spark gap which is automatically setin operation when the engine is running and which is cut out ofoperation when the engine is stopped.

The provision of an auxiliary spark gap has the effect of increasing theintensity of the spark produced at the electrodes in the combustionchamber of an internal combustion engine, and consequently adds to theefficiency of operation thereof. In order to facilitate starting of theengine it is desirable that the auxiliary spark gap be initially cut outof operation so that even a comparatively weak ignition current will betransmitted directly to the sparking electrodes.

It is also desirable that the auxiliary spark gap be initiallyshort-circuited and subsequently intermittently short-circulted toprevent injury to the coil by the extremely high voltage current whichis present in the ignition system as a result of the auxiliary sparkgap. 7

It is an object therefore of the present invention to provide a sparkplug including an auxiliary spark gap which is automaticallyshort-circuited prior to the starting of the engine on which the sparkplug is mounted.

It is another object of this invention to provide a spark intensifyingmeans adapted to be set in operation by the vibration of an internalcombustion engine or of a vehicle on which the engine is mounted.

It is a further object of this invention to provide a spark plugincluding an intensifying spark gap adapted to be set in operationautomatically by vibration regardless of the position of the spark plug.

It is an important object of this invention to provide sparkintensifying means which Figure 2 is a fragmentary central verticalsection showing the construction of the auxiliary spark gap.

Figure 3 is a section on the line 33 of Figure 2.

Figure 1 is a section similar to Figure 2 showing the spark gap cut outof operation.

Figure 5 is a section similar to Figure 2 showing a preferredconstruction for a hori zontal spark plug.

Figure 6 is a section on the line 66 of Figure 5.

Figure 7 is a section similar to Figure 5 showing the spark gap cut outof operation.

As shown on the drawings:

The spark intensifying means of this invention are adapted to be used inconnection with any standard spark plug and are preferably an integralpart of the spark plug construction.

The spark plug which is shown herein for purposes of illustration,comprises the usual metallic shell 1 which is adapted to be engaged in athreaded aperture leading into the combustion chamber of an internalcombustion engine and which is provided with the usual sparkingelectrode 2. Se-

' cured axially in said shell 1 by means of the usual locking sleeve 3is an insulator 4: which is constructed of porcelain or other suitablematerial and which has axially mounted therein a central sparkingelectrode 5 which extends downwardly through said insulator and throughthe interior of the shell 1 to a position opposite the sparkingelectrode 2 as shown in Figure 1. Said electrode 5 extends to the levelof the upper surface of the insulator 4t and mounted on the upper end ofsaid insulator is a metallic cap 6 which is provided with an integralupwardly extending threaded terminal post 7 adapted to receive a usualbinding nut 9. Said cap 6 is preferably secured by crimping or spinningthe lower edge of said cap in a peripheral groove formed near the upperend of the insulator 4, and the interior of said cap is cut away toafford a recess 9 which separates the cap from the end of the electrode5 and affords an auxiliary or intensifying spark gap. Extending upwardlyfrom said recess 9 is a recess 10 which is formed in the cap 6 directlyabove the electrode 5 and which is adapted loosely to receive a metallicball 11 of greater diameter than the depth of the recess 9.

It is apparent from this construction that when the engine on which thespark plug is mounted is not in operation the ball 11 will remain seatedon the upper end of the electrode 5 thus completing the circuit betweensaid electrode and the cap 6 and short-circuiting the auxiliary sparkgap afforded by the recess 9. After the engine is started the vibrationthereof, and in case of use on motor vehicles the vibration of thevehicle, will cause the ball 11 to be thrown into the chamber 10 in theposition shown in Figure 2 and the auxiliary intensifying spark gap willconsequently be put in operation.

In the construction shown in Figures 5, 6 and 7, the interior of the cap6 is cut away to form. a frustro-conical chamber '2 instead of thecylindrical chamber 10 so that when the engine is not in operation theball 11 will move by gravity to the position indicated in Figure 7, andconsequently short-circuit the auxiliary spark gap.

It will accordingly be observed that this invention provides meansaffording an in tensifying spark gap which is inherent in the spark plugitself and which is automatically short-circuited or cut out ofoperation when the engine is not running, so that the starting of theengine is facilitated.

When the engine is running the vibration thereof tends to move the ball11 away from the end of the electrode and thus creates the auxiliaryintensifying spark gap which adds greatly to the efliciency of theengine on which the spark plug is mounted.

It is, of course, understood that this in.- vention is not limited toconstructions wherein. the intensifying spark gap assem bly is inherentin the spark plug, but that many details of construction may be variedthrough a wide range, and it is therefore not purposed to limit thepatent otherwise than necessitated by the prior art.

I claim as my invention:

1. In a spark plug, an insulator, an electrode extending to the outerend thereof, a terminal cap from the insulator separated from theelectrode to afford an auxiliary spark gap, and a metallic spheremovably retained within said cap and adapted in certain positions tosii'nultaneously contact both the electrode and the cap, and in otherpositions to be out of contact with one of them.

2. In a spark plug, an electrode, a con ducting member spaced away fromsaid electrode, to afford an auxiliary spark gap, said member includingguiding means, and a gravity operated device cooperating with saidguiding means to bridge said spark gap when in the position to which itis moved by gravity.

In a spark plug, a body of insulation, an electrode extendingtheretln'ough, a cap spaced away from one surface of said body, and aloose conductor between said body and said cap, the distance that thecap is spaced away from said surface being in general smaller than thedimensions of said con ductor, said distance increasing at a pointadjacent said electrode whereby at such point suflicient room isafforded for said conductor.

l. In a spark plug, a body of insulation, an electrode extendingtherethrough and terminating at one end flush. with one end surfacethereof, a cap secured over said end, loose connecting means normallyheld by gravity in contact with said electrode end, and means forkeeping said loose connecting means near said electrode end. wherebywhen said loose means is moved against gravity a spark gap will beprovided at said electrode end.

In a spark plug, a central electrode having a plurality of spark gaps,and a member normally closing one of said gaps and susceptible ofmovement by vibration forces to open said gap.

6. In a spark plug, an insulated electrode having air gaps at each end,and a movable member normally closing one of said gaps and adaptedintermittently to vary said gap.

In testimony whereof I have hereunto subscribed my name in the presenceof two suoscribing witnesses.

IVILLARD E. LYONS.

itnesses CHARLES IV. Hints, Jr, CARLTON HILL.

